With the world's energy and environmental problems getting worse, the electrical energy as a clean energy source is widely used in automotive field, which provides a broad space of application for electric vehicles. However, due to the limitation of current battery energy density, the mileage range of electric vehicles is generally between one hundred to two hundred kilometers, which is far less an endurance mileage of conventional cars. Therefore, whether we can quickly provide energy supplies to cars directly affects the popularization and application of electric vehicles. Charging the battery takes a few hours to complete, and fast charge can impact the lifetime of the battery, at the same time, a single battery is very heavy, which is not convenient to replace manually. In response to this problem, researching robot for being able to replace the battery quickly is the only effective way to provide the rapid supply of vehicle energy.
There are mainly two energy supply methods, battery charging and battery changing for existing electric vehicles. There are lots of inefficiency in the charging mode, mainly because a full charge takes a long time; charging equipments need to be combined with long-term parking position, the layout of charging facilities lacks flexibility; outdoor charge can not be made in a cold climate of the northern winter; the batteries have no unified maintenance and management, which impacts the recycling lifetime of the batteries. In comparison, the battery changing way is provided with many significant advantages, for example, supplying energy fast (rapid electricity supply), less impact on battery life, easy to achieve commercialization, etc., which have obtained wide recognition from electric vehicle manufacturers, battery manufacturers and charge operators and so on.
In the context of intensive introduction of the policies for Chinese new energy automobile industry, the electricity charging station market of the domestic electric vehicles has started rapidly, and automatic battery changing technology has matured for electric buses, sanitation trucks and other models. But being subject to the constraints of the related technologies and the maturity of the industry, the automatic battery changing technology of electric passenger vehicles is still at the exploratory stage of development. In this case, the development of service network for intelligent electricity charging of electric passenger vehicles must rely on the innovation of battery changing technology to really promote the healthy and sustainable development of the electric vehicle industry.
An invention patent with Patent No. CN101559758A discloses a quick-change system which serves to support the chassis battery. This system is unable to achieve the automatic changing of the battery because this system only consists of interconnecting members between the battery and the vehicle, and does not have any positioning and guiding devices. An invention patent with Patent No. CN201784595U discloses an automatic changing system of the battery for electric vehicles, comprising the vehicle positioning platform, lifting equipment, etc. Because the positioning platform of this system can only locate the vehicles in the front and rear direction, if there has an angle (the chassis is tilted to a certain angle) between the chassis of electric vehicle for changing and the horizontal, when the lifting equipment is lifting battery box, it will cause excessive lifting or lifting without reaching the desired place, causing potential security risks for the vehicle after battery changing. Meanwhile, this system has proposed a changing method of the chassis battery and a method using an inclined plane pin to position the battery, but the error of this method used to position the battery in such a purely mechanical manner is large, and there is no information feedback, which is easy to damage the battery. Secondly, the system does not have the function of automatic battery identification.
Therefore, it is desired to develop a control system and a control method allowing the automatic identification of the battery and accurately positioning between the battery and the vehicle chassis to achieve fast, accurate and secure energy supplies of the electric vehicles, thereby contributing to the promotion and application of the electric cars.